And another problem exits.

The solution above works for "create a new article" in the frontend. But if I edit an existing article, K2 opens not in a new box. It will be open in the same windows and I cannot close this window with "save" or "close".

Does anybody share my problem?

Hello,

Can you try the same with the default template?
This sounds more like a template issue.

Hi. I have 2 sites with K2 v2.7 on J3.5. Both are running PHP 5.6.19 on the same server.
I also confirm Miroslav solution but only for items.
It did not solve the issue in categories.
This goes for both sites.

276-279 in administrator/components/com_k2/models/item.php
Change '===' by '==' resolved the issue.

Thank you Ami for your feedback :)

No I cann't try it.

In backend Administrator/Components/com_k2 which folder?

In root/components/com_k2/templates/defalut/item.php I can not find a "===" triple to replace it.
and the same in the templates/mytempl/html/com_k2/templates/default/item.php

So where is it to fix?

I fix that in item.php file (K2 administrator\components\com_k2\models) and alternated lines (around 276-279):

Or you can use the DEV version - github.com/getk2/k2/archive/master.zip

Miroslav wrote: I fix that in item.php file (K2 administrator\components\com_k2\models) and alternated lines (around 276-279):
if (($files === 0 || $existingImage) && !JRequest::getBool('del_image'))
changed to
if (($files == 0 || $existingImage) && !JRequest::getBool('del_image'))

and
if ($files === 0)
changed to
if ($files == 0)

It works!

Same issue here on 2.7 and 3.5 both fresh installations.

Thanks Miroslav! Anyone know if I can do this as an override in my template? I tried adding it to a:

TEMPLATE\html\com_k2\models\item.php

but it doesn't work..

The model cannot be overridden, but there is no reason to worry about this.
It is already included in the DEV version and it will be included in the next stable release.

Still having the infamous image was not uploaded. Please ensure that ....
The chunk of code in administrator/components/com_k2/models/item.php in my test installation is a bit different from the one mentioned by Miroslav.
This is what I've found at lines around 276-279.
which does not correspond with the one mentioned in this forum.

I'm not using any other extensions, only K2.7 and J3.5.1 on.PHP 5.4.16
Anyway, trying to replae '===' with '==' does not seem to solve the issue.
Any idea?